It looks like res_search is the culprit here and what it's searching for (smtp-server.nycap.rr.com) is producing the error. According to netdb.h (I think) that error is either non-authoritative host or SRVFAIL.

Checking dns, it does look like something's wrong with that host (please forgive the use of nslookup) :

I want to say it looks like a forward/reverse mismatch, but I could be wrong. It could just be one bad entry in their mailcluster. I'm thinking the reason that it works in the debug mode is that ruleset 3 is skipped and part of that ruleset is doing reverse lookups on the destination mailserver.